Deauville Score 3 at End of Treatment in NHL
Yes, a Deauville score of 3 is considered a complete metabolic response at the end of treatment in non-Hodgkin lymphoma (NHL), specifically for FDG-avid histologies including DLBCL and follicular lymphoma. 1
Evidence-Based Interpretation
The Lugano Classification (2014), which represents the authoritative guideline for lymphoma response assessment, explicitly states that complete metabolic response is defined as a Deauville score of 1,2, OR 3 with or without a residual mass on the 5-point scale 1. This applies to end-of-treatment assessment in NHL.
Key Context from Guidelines
The Lugano criteria specifically note that:
Most patients with uptake higher than mediastinum but less than or equal to liver (score of 3) have good prognosis at the end of treatment with standard therapy in Hodgkin lymphoma, DLBCL, and follicular lymphoma 1
The interpretation acknowledges that FDG uptake declines during therapy in chemotherapy-sensitive disease, and residual uptake higher than normal liver is frequently seen at interim in patients who ultimately achieve complete metabolic response 1
Critical Caveat: Context Matters
However, there is an important exception: In response-adapted trials exploring treatment de-escalation, a more cautious approach may be preferred, judging a score of 3 to be an inadequate response to avoid undertreatment 1. Therefore, interpretation of a score of 3 depends on:
- Timing of assessment (interim vs. end of treatment)
- Clinical context (standard therapy vs. response-adapted protocols)
- Treatment intent (curative vs. palliative)
Supporting Research Evidence
Recent studies corroborate this guideline interpretation:
A 2024 pathologic validation study found that DS ≤ 3 lesions were true-negative except for one case (8.3%) diagnosed with lymphoma on follow-up 2
A 2022 study in DLBCL showed that patients with DS 3 at end of treatment, when combined with low IPI scores, had extremely low risk of disease progression (HR 0.06) 3
A 2016 study confirmed that using liver as the visual reference (which defines DS 3) improved specificity while maintaining high sensitivity 4
Practical Algorithm
For standard curative therapy in NHL:
- DS 1-3 at end of treatment = Complete metabolic response
- No additional treatment needed
- Proceed to surveillance
For response-adapted protocols or treatment de-escalation trials:
- DS 1-2 = Complete metabolic response
- DS 3 = Consider inadequate response
- May require biopsy or continued full-intensity therapy
If uncertainty exists with DS 3:
- Consider biopsy confirmation before changing treatment plan 1, 2
- Obtain follow-up scan in 6-8 weeks
- Integrate with CT size reduction (>30% reduction supports complete response) 5
The RECIL 2017 criteria further support this by defining CR as Deauville score 1-3 with complete normalization of FDG-PET uptake 5, 6.